How to heal

I’m very stable and in love in my relationship and of course every relationdhip goes through hard times but I am still stung badly by things that happened 2 years ago, the last thing that hurt me happened in febuary and I won’t go into details but it’s caused a lot of hurt and worry and high alertness in me. My partner is understanding and reassures me every step of the way but I am tired of the pain and I really want to know how to start healing.